Molded pallet

ABSTRACT

Resin impregnated wood fibrous material is molded to form a rectangular deck member and a set of separate elongated hollow leg members. The deck member has a generally uniform wall thickness and defines parallel spaced downwardly projecting reinforcing ribs, and the side walls of each of the leg members have teeth-like projections which extend upwardly between the ribs. The leg members are spaced laterally across the deck member and are secured to the underneath surface of the deck member by a waterproof adhesive. The leg members have outer surfaces perpendicular to the deck member to provide for storing loaded pallets within a rack, and define longitudinally spaced recesses to provide for four-way entry by a fork lift truck. The bottom wall portion forming each recess is spaced from the underneath surface of the deck member to define a longitudinally extending chamber within each leg member for receiving an optional rigid longitudinally extending reinforcing member.

United States Patent 1 Munroe 1 1 MOLDED PALLET [76] Inventor: 'ThomasMunroe, c/o Moraine Box Company, PO. Box 538, Dayton,

Ohio 45419 [22] Filed: Aug. 13, 1970 [21] Appl. No.: 63,573

[52] U.S. Cl. ..108/58, 108/51, 108/53 [51] Int. Cl. ..B65d 19/38 [58]Field of Search ..108/51-58 [56] References Cited UNITED STATES PATENTS3,359,929 12/1967 Carlson v ..108/58 3,424,110 l/1969 Toot ..108/533,611,952 10/1971 Hoffman ..108/58 2,455,197 11/1948 Sullivan ..108/523,511,191 5/1970 Berry, Jr. et a1.... ..108/58 1,612,382 12/1926 Lehman..108/58 2,501,506 3/1950 George ..108/52 2,570,326 10/1951 Angelis108/51 X 2,615,661 10/1952 Cushman ..108/52 2,928,638 3/1960 Parker..108/52 3,187,691 6/1965 Leitzcl ..108/58 3,526,195 9/1970 Maryonovich..108/53 ]March 13, 1973 Primary Examiner-Bobby R. Gay AssistantExaminer-Glenn O. Finch Attorney-Marechal, Biebel, French & Bugg [57]ABSTRACT Resin impregnated wood fibrous material is molded to form arectangular deck member and a set of separate elongated hollow legmembers. The deck member has a generally uniform wall thickness anddefines parallel spaced downwardly projecting reinforcing ribs, and theside walls of each of the leg members have teethlike projections whichextend upwardly between the ribs. The leg members are spaced laterallyacross the deck member and are secured to the underneath surface of thedeck member by a waterproof adhesive. The leg members have outersurfaces perpendicular to the deck member to provide for storing loadedpallets within a rack, and define longitudinally spaced recesses toprovide for four-way entry by a fork lift truck. The bottom wall portionforming each recess is spaced from the underneath surface of the deckmember to define a longitudinally extending chamber within each legmember for receiving an optional rigid longitudinally extendingreinforcing member.

11 Claims, 10 Drawing Figures PATENTEUHAR 1 3197s SHEET 10F 2 FIG-4 m Tu wR W M s A M O H T MOLDED PALLET BACKGROUND OF THE INVENTION In theart of material handling pallets, there has been considerable effort toproduce a pallet which is less expensive than the standard palletconstructed of lumber and which provides substantially the samestrength, durability, and other desirable characteristics. For example,the pallet shown in US. Pat. No. 3,140,672 is molded from a wood fibrousmaterial impregnated with resin, and the pallet disclosed in US. Pat.No. 3,199,469 is molded of a thermoplastic material which may have awood filler. Other molded pallets are shown in U.S. Pat. Nos. 3,187,691,3,359,929 and 3,481,285.

It has been found desirable for any pallet to provide a number offeatures. For example, a pallet should not only be durable, warpresistant and provide substantial strength, it should also beinexpensive and lightweight in construction. It is also desirable for apallet to be nestable, moisture resistant and have smooth exposed edgesand surfaces. In addition, both the top and bottom surfaces of thepallet should be of substantial area so that the articles stacked on thepallet are not subject to undesirable stresses, and loaded pallets maybe stacked without the legs of the pallets damaging the articles on thepallet below.

A bottom surface of large area is also desirable on a pallet fortransporting the pallets along a roller conveyor where the rollers arespaced, for example, at a distance of 9 inches. Another importantfeature on a pallet is for the edge surfaces to be substantiallyperpendicular to the deck of the pallet so that loaded pallets may bestored within a rack having opposed support tracks or flanges. It isalso desirable for a pallet to be conveniently constructed in variouswidths, for example, between 31 inches and 40 inches. l-leretofore,molded pallets have been constructed with one or more molds or dies foreach size or design.

After a careful study of the molded pallets disclosed in the abovepatents, it is apparent that each of the pallets does not provide one ormore of the desirable features mentioned above.

SUMMARY OF THE INVENTION The present invention is directed to animproved molded pallet which provides all of the aforementioned featuresand advantages and, in addition, provides for increasing the strengthand rigidity of the pallet if desirable for handling an unusually heavyload. In accordance with a preferred embodiment of the invention, agenerally flat deck member is molded from a resin impregnated woodfibrous material and includes longitudinally spaced parallel ribs whichproject downwardly. The deck member has a generally uniform wallthickness forming a corrugated cross-sectional configuration withlaterally extending parallel spaced grooves within the upper surface ofthe deck member.

A plurality of elongated hollow leg members are each molded of thesameresin impregnated wood fibrous material, and the side walls of eachleg member have teeth-like projections which extend upwardly between theribs on the underneath surface of the deck member. The leg members arearranged in laterally spaced relation and are bonded to the underneathsurface of the deck member by a suitable water resistant adhesive sothat a watertight chamber is formed within each leg member. Theinterfitting relation between the teeth-like projections on each legmember and the underneath surface of the ribbed deck member provides asubstantial area for adhesive bonding and also provides for a positiveinterfitting connection between the leg and deck members.

The outer side wall and'the end surfaces of the leg members aresubstantially perpendicular to the deck member, and the inner side wallsurfaces are slightly inclined. Each of the leg members defineslongitudinally spaced recesses to provide for four-way entry of a forklift truck, and the wall portion defining each recess is spaced from theunderneath surface of the deck.member so that a rigid plank-likereinforcing member may be inserted within each leg to provide additionalstrength and rigidity.

Other features and advantages of the invention will be apparent from thefollowing description, the accompanying drawings and the appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view ofapallet constructed in accordance with the invention and showing the topsurface;

FIG. 1A is a fragmentary perspective view showing a modification of thepallet in FIG. 1;

FIG. 2 is another perspective view of the pallet in FIG. 1 and showingthe bottom surfaces of the pallet;

FIG. 3 is an exploded section taken generally on the line 3-3 of FIG. 1and with portions broken away;

FIG. 4 is a similar exploded fragmentary section taken generally on theline 44 of FIG. 3;

FIG. 5 is an exploded fragmentary perspective view showing amodification of the pallet in FIGS. 1 and 2;

FIG. 6 is a fragmentary perspective view showing another modification ofthe pallet;

FIG. 7 is an exploded perspective view showing a further modificationofthe pallet in FIGS. 1 and 2;

'FIG. 8 is a schematic elevational end view showing another modifiedform of the pallet in FIGS. 1 and 2; and

FIG. 9 is a schematic end view of a plurality of pallets of FIGS. 1 and2 stacked in offset nested relation.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The pallet shown in FIGS. 1 and2 is molded in sections from a resin impregnated wood fibrous material,preferably using a molding technique perfected by Werzalit-Pressholzwerkof 7l4l Oberstenfeld bei Stuttgart, West Germany and promoted in theUnited States under the trademark Werzalit." The first section of thepallet includes a generally flat rectangular deck member 15 having agenerally uniform wall thickness and defining longitudinally spaced anddownwardly projecting parallel ribs 1.6.As a result of the uniform wallthickness, each of the ribs 16 defines a laterally extending groove 18within the flat upper surface 20 of the deck member. The opposite endportions 22 of the deck member 15 form rails having a thicknesscorresponding to the thickness of the center portion of the deck memberincluding the ribs 16. Thus the deck member has a uniform corrugatedcross-sectional configuration across its width and transversely to theribs 16, and could possibly be extruded with sufficiently largeequipment.

The other sections of the pallet include a set of elongated hollow endand center leg members 25 and 26 respectively, each of which is moldedof resin impregnated wood fibrous material in the same manner as thedeck member and has a generally uniform wall thickness. Each of the legmembers 25 and 26 includes a bottom wall 28, opposite flat side walls 30and 31 and flat end walls 32. Two longitudinally spaced recesses 34 areformed within each bottom wall 28 by an inverted U-shaped wall portion36 which extend upwardly approximately one-half the height of the legmember. The side walls 30 and 31 of each leg member 25 include aplurality of longitudinally spaced and upwardly extending teeth-likeprojections 37 which define correspondingly spaced recesses or cavities38.

The projections 37 and the cavities 38 conform to the configuration ofthe underneath surface of the deck member 15, and each of the legmembers 25 and 26 is secured to the underneath surface of the deckmember 15 by a suitable water resistant adhesive to form a substantiallywatertight chamber within each of the leg members. As shown in FIG. 4,the outer surface of the outer side wall 30 of the two outermost legmembers 25 and the end walls 32 of each leg member extend substantiallyperpendicular to the deck member 15. The inner side wall 31 of the twoleg members 25 and both of the side walls of the center leg member 26are slightly inclined or tapered to facilitate molding each of the legmembers as an integral body. Preferably, the projections 37 along thetapered side walls 31 also extend or curve outwardly of the leg membersto provide additional reinforcement and a greater surface area forgluing or bonding the leg members to the underneath side of thedeck-members. These extended projections 37 also eliminate sharp cornerswithin the grooves between the ribs 16 so that foreign matter does nottend to accumulate.

Referring to FIG. 1A which shows a modification of the pallet in FIGS.1-4, the end portions 22 of the deck member 15 are provided with threelaterally spaced slots or recesses 42 which receive an extended upperlip or edge portion 43 of the end wall 32 of the corresponding legmember. This modification has the advantage of providing an increasedsurface area for adhesive bonding the end walls 32 of each leg member tothe underneath surface of the deck member 15 and to provide a somewhatmore positive interfitting connection between the leg members and thedeck member.

As mentioned above, the recesses 34 are defined within each of the legmembers 25 and 26 by a bottom wall portion 36 (FIG. 7) which is spacedfrom the underneath surface of the ribs 16 to define within each legmember a chamber or cavity which extends the full length of the legmember. To increase the longitudinal bending strength of the palletshown in FIGS. 1 and 2, an elongated plank-like reinforcing member 50(FIG. 7) may be inserted within each of the leg members 25 and 26.Preferably, the member 50 is formed of plywood and has a thickness whichcorresponds to the distance between the underneath surfaces of the ribs16 and the upper surfaces of the bottom wall portions 36 so that themember 50 is sandwiched between the surfaces.

Referring to FIG. 5 which shows another modified pallet of theinvention, the opposite end portions of the pallet shown in FIGS. 1 and2 may each be reinforced by a metal frame 55 consisting of a laterallyextending angle member 56 rigidly secured to angle corner posts or legs57. The angle member 56 extends into a corresponding laterally extendingslot 58 formed within the end portion 22' of the deck member 15', andthe leg members 57 are secured to the outer corners of the molded legmembers 25 by a set of suitable fasteners such as screws 59.

As shown in FIG. 6, notches 62 are formed within a set of laterallyaligned projections 36 on the side walls 30 and 31 of the leg members 25and 26, and a laterally extending channel member 64 is inserted into thenotches 62 adjacent the underneath surface of the deck member 15. Thechannel member defines a laterally extending slot for receiving asuitable strap or band (not shown) for securing a load of cargo to thedeck member 15. While only one laterally extending slot is illustratedin FIG. 6, it is to be understood that a plurality of longitudinallyspaced slots may be employed according to the number of tie down bandsdesired. The channel member 64 provides for guiding the end of a bandthrough the slot and cooperates with the ribs 16 to provide lateralrigidity and strength to the deck member 15.

In accordance with another embodiment of the invention, a molded deckmember 15 (FIG. 8) is cemented or bonded to a set of elongated moldedleg members 65 which are molded and formed in the same manner as the legmembers 25 and 26 described above. The leg members 65, however, have awidth approximately one-half the width of the leg members 25 and 26 andare particularly adapted for use on a pallet having a width less thanthe standard 40". As shown in FIG. 8, two of the leg members 65 may bejoined back to back with their vertical side walls abutting to form thecenter leg member. As illustrated in FIG. 9, a number of the palletsshown in FIGS. 1 and 2 may be stacked in interfitting nested relation byoffsetting alternate pairs of adjacent pallets having their loadsupporting surfaces in abutting relation. This substantially reduces thespace required to store or transport a number of pallets.

From the drawings and the above description, it is apparent that apallet constructed in accordance with the present invention provides thedesirable features and advantages mentioned above. For example, thecombination of the deck member 15 with parallel spaced ribs 16 and theinterfitting elongated hollow leg member 25 and 26, which are separatelymolded from resin impregnated wood fibrous material and are bondedtogether with adhesive, provides for a lightweight pallet of substantialstrength and with smooth edges and surfaces. As a result of therelatively narrow parallel spaced ribs 16, the area of the top surface20 is approximately percent of the total area of the deck member,thereby providing a load supporting surface of substantial area.

The leg members 25 and 26 provide additional important features. Thatis, the flat pads formed by the bottom walls 28 of the leg membersprovide a bottom supporting surface of substantial area in the order of39% of the total area of the deck member 15. This large bottomsupporting area is desirable to prevent damage ing loaded pallets alonga roller conveyor. As indicated in FIG. 9, the leg members 25 and 26also provide for nesting of the pallets, and the outer perpendicularwalls 30 and 32 of the leg members enable a loaded pallet to be storedin a rack having opposed flanges which engage the outer edge portions ofthe bottom walls 28. The wide flat bottom wall 28 of the center legmember (FIGS. 2 and 8) also provides for lifting a loaded pallet withlift truck forks which engage only two of the leg members and withoutthe loaded pallet tipping as occurs with conventional four-way entrywood pallets.

' The construction of the separate deck and leg members also providesfor producing pallets of various widths. That is, as a result of theuniform longitudinal cross-sectional configuration of the deck member15, the deck member maybe out according to a desired width after whichthe leg members are secured to the underneath surface of the deck memberas shown in FIGS. 1-4. As mentioned above, to construct a relativelynarrow pallet, the invention provides for using narrower leg members 65(FIG. 8) and attaching two of the'leg members 65 together to form aunitary center leg member while retaining the ability to nest thepallets in a manner as shown in FIG. 9.

The modifications shown in FIGS. 5-7 provide additional features. Theend frames 55 not only provide for lateral reinforcement of the deckmember but also protect the end and corner surfaces of the pallet. Theoptional plank-like reinforcing members 50 enable the strength of thepallet to be conveniently increased in a longitudinal direction, and thechannel members 64 (FIG. 6) provide for conveniently inserting tie downstraps or bands under the deck member 15 and for increasing the strengthin a lateral direction.

While the forms of pallets herein described constitute preferredembodiments of the invention, it is to be understood that the inventionis not limited to these precise forms of pallets, and that changes maybe made therein without departingfrom the scope of the invention whichis defined in the appended claims. For example, it is within the scopeof the invention to-construct and locate the hollow molded leg membersso that a peripheral edge portion of the deck member projects from theleg members if storage in a rack is not required and it is desirable toshrink-fit a plastic film over a load on the pallet.

What is claimed is:

l. A pallet comprising a molded rectangular deck member forming a loadsupporting upper surface and including a plurality of substantiallyparallel spaced integral reinforcing ribs, said deck member having asubstantially uniform wall thickness forming a corrugated crosssectionalconfiguration relative to said ribs and defining downwardly facingparallel spaced grooves,

at least two separate elongated molded hollow leg members arranged inspaced relation below said deck member and extending transversely ofsaid ribs, each said leg member including a bottom wall forming agenerally flat bottom surface and side walls projecting upwardly fromsaid bottom wall, the upper portions of said side walls of each said legmember including teeth members projecting upwardly into said grooves andbetween said ribs,

said leg members each having at least one longitudinally extending saidside wall inclined relative to said bottom wall, said leg membersarranged to provide offset nesting of a pair of adjacent said palletswith said leg members disposed in interfitting relation, and I means forsecuring the upper portions of said side walls of each said leg memberto the underneath surface of said deck member.

2. The pallet as defined in claim 1 wherein said deck member and saidleg members each comprise a discrete unitary body consisting of resinimpregnated wood fibrous material, and said securing means comprise anadhesive bonding said leg members to said deck member.

3. A pallet as defined in claim 1 wherein the outermost said leg memberseach has outer surfaces extending substantially perpendicular to saiddeck member to facilitate supporting said pallet on opposing horizontalflanges of a storage rack.

4. A pallet as defined in claim 1 wherein said deck member has a uniformcross-sectionalconfiguration along its width to provide for locatingsaid leg members at various laterally spaced intervals and therebyfacilitate construction of pallets of different widths.

5. A pallet as defined in claim 1 wherein said bottom wall of each saidleg member defines a set of longitudinally spaced recesses adapted toreceive the forks of a lift truck.

. 6. A pallet as defined in claim 7 wherein each said recess of at leastone of said leg members is defined by a wall portion spaced from theunderneath surface of said deck member to define a longitudinallyextending chamber within said leg member, an elongated rigid reinforcingmember extending within said chamber, and said reinforcing member has athickness corresponding substantially to the distance between said wallportions of said recesses and the underneath surfaceof said deck member.

7. A pallet as defined in claim 1 including means extending between twoadjacent said ribs of said deck member to define a slot adapted toreceive a tie down strap.

8. A pallet as defined in claim 1 including a rigid metal frameextending along at least one lateral edge of said deck member, and saidframe includes leg portions positioned adjacent the outer corners of theoutermost said leg members.

9. A pallet as defined in claim 1 wherein the center portion of saiddeck member is supported by a pair of said leg members each having asubstantially perpendicular longitudinallyextending side wall and aslightly inclined longitudinally extending side wall relative to saiddeck member, and said perpendicular side walls are disposed in adjacentrelation.

10. A pallet as defined in claim 1 wherein said deck member has asubstantially uniform wall thickness and a corrugated cross-sectionalconfiguration transversely of said ribs, and each said leg memberextends substantially the full length of said deck member.

1 l. A pallet as defined in claim 1 wherein at least one of said legmembers includes substantially flat end walls, means defining recesseswithin the underneath surface of said deck member for receiving theupper portions of said end walls, and said securing means comprise anadhesive which extends into said recesses for securing said end walls tosaid deck member.

1. A pallet comprising a molded rectangular deck member forming a loadsupporting upper surface and including a plurality of substantiallyparallel spaced integral reinforcing ribs, said deck member having asubstantially uniform wall thickness forming a corrugatedcross-sectional configuration relative to said ribs and definingdownwardly facing parallel spaced grooves, at least two separateelongated molded hollow leg members arranged in spaced relation belowsaid deck member and extending transversely of said ribs, each said legmember including a bottom wall forming a generally flat bottom surfaceand side walls projecting upwardly from said bottom wall, the upperportions of said side walls of each said leg member including teethmembers projecting upwardly into said grooves and between said ribs,said leg members each having at least one longitudinally extending saidside wall inclined relative to said bottom wall, said leg membersarranged to provide offset nesting of a pair of adjacent said palletswith said leg members disposed in interfitting relation, and means forsecuring the upper portions of said side walls of each said leg memberto the underneath surface of said deck member.
 1. A pallet comprising amolded rectangular deck member forming a load supporting upper surfaceand including a plurality of substantially parallel spaced integralreinforcing ribs, said deck member having a substantially uniform wallthickness forming a corrugated cross-sectional configuration relative tosaid ribs and defining downwardly facing parallel spaced grooves, atleast two separate elongated molded hollow leg members arranged inspaced relation below said deck member and extending transversely ofsaid ribs, each said leg member including a bottom wall forming agenerally flat bottom surface and side walls projecting upwardly fromsaid bottom wall, the upper portions of said side walls of each said legmember including teeth members projecting upwardly into said grooves andbetween said ribs, said leg members each having at least onelongitudinally extending said side wall inclined relative to said bottomwall, said leg members arranged to provide offset nesting of a pair ofadjacent said pallets with said leg members disposed in interfittingrelation, and means for securing the upper portions of said side wallsof each said leg member to the underneath surface of said deck member.2. The pallet as defined in claim 1 wherein said deck member and saidleg members each comprise a discrete unitary body consisting of resinimpregnated wood fibrous material, and said securing means comprise anadhesive bonding said leg members to said deck member.
 3. A pallet asdefined in claim 1 wherein the outermost said leg members each has outersurfaces extending substantially perpendicular to said deck member tofacilitate supporting said pallet on opposing horizontal flanges of astorage rack.
 4. A pallet as defined in claim 1 wherein said deck memberhas a uniform cross-sectional configuration along its width to providefor locating said leg members at various laterally spaced intervals andthereby facilitate construction of pallets of different widths.
 5. Apallet as defined in claim 1 wherein said bottom wall of each said legmember defines a set of longitudinally spaced recesses adapted toreceive the forks of a lift truck.
 6. A pallet as defined in claim 7wherein each said recess of at least one of said leg members is definedby a wall portion spaced from the underneath surface of said deck memberto define a longitudinally extending chamber within said leg member, anelongated rigid reinforcing member extending within said chamber, andsaid reinforcIng member has a thickness corresponding substantially tothe distance between said wall portions of said recesses and theunderneath surface of said deck member.
 7. A pallet as defined in claim1 including means extending between two adjacent said ribs of said deckmember to define a slot adapted to receive a tie down strap.
 8. A palletas defined in claim 1 including a rigid metal frame extending along atleast one lateral edge of said deck member, and said frame includes legportions positioned adjacent the outer corners of the outermost said legmembers.
 9. A pallet as defined in claim 1 wherein the center portion ofsaid deck member is supported by a pair of said leg members each havinga substantially perpendicular longitudinally extending side wall and aslightly inclined longitudinally extending side wall relative to saiddeck member, and said perpendicular side walls are disposed in adjacentrelation.
 10. A pallet as defined in claim 1 wherein said deck memberhas a substantially uniform wall thickness and a corrugatedcross-sectional configuration transversely of said ribs, and each saidleg member extends substantially the full length of said deck member.